Avoiding duplicate calls to Bitmap.getPixel(x, y)

Change-Id: I24414b41e9b0e9833cd4e962187a08672bc86c46

1 files changed, 24 insertions, 20 deletions

diff --git a/src/com/android/launcher3/Utilities.java b/src/com/android/launcher3/Utilities.java
index b6876f670..71677782d 100644
--- a/src/com/android/launcher3/Utilities.java
+++ b/src/com/android/launcher3/Utilities.java
@@ -309,6 +309,9 @@ public final class Utilities {
         float highScore = -1;
         int bestHue = -1;
 
+        int[] pixels = new int[samples];
+        int pixelCount = 0;
+
         for (int y = 0; y < height; y += sampleStride) {
             for (int x = 0; x < width; x += sampleStride) {
                 int argb = bitmap.getPixel(x, y);
@@ -326,6 +329,9 @@ public final class Utilities {
                     // Defensively avoid array bounds violations.
                     continue;
                 }
+                if (pixelCount < samples) {
+                    pixels[pixelCount++] = rgb;
+                }
                 float score = hsv[1] * hsv[2];
                 hueScoreHistogram[hue] += score;
                 if (hueScoreHistogram[hue] > highScore) {
@@ -335,31 +341,29 @@ public final class Utilities {
             }
         }
 
-        SparseArray<Float> rgbScores = new SparseArray<Float>();
+        SparseArray<Float> rgbScores = new SparseArray<>();
         int bestColor = 0xff000000;
         highScore = -1;
         // Go back over the RGB colors that match the winning hue,
         // creating a histogram of weighted s*v scores, for up to 100*100 [s,v] buckets.
         // The highest-scoring RGB color wins.
-        for (int y = 0; y < height; y += sampleStride) {
-            for (int x = 0; x < width; x += sampleStride) {
-                int rgb = bitmap.getPixel(x, y) | 0xff000000;
-                Color.colorToHSV(rgb, hsv);
-                int hue = (int) hsv[0];
-                if (hue == bestHue) {
-                    float s = hsv[1];
-                    float v = hsv[2];
-                    int bucket = (int) (s * 100) + (int) (v * 10000);
-                    // Score by cumulative saturation * value.
-                    float score = s * v;
-                    Float oldTotal = rgbScores.get(bucket);
-                    float newTotal = oldTotal == null ? score : oldTotal + score;
-                    rgbScores.put(bucket, newTotal);
-                    if (newTotal > highScore) {
-                        highScore = newTotal;
-                        // All the colors in the winning bucket are very similar. Last in wins.
-                        bestColor = rgb;
-                    }
+        for (int i = 0; i < pixelCount; i++) {
+            int rgb = pixels[i];
+            Color.colorToHSV(rgb, hsv);
+            int hue = (int) hsv[0];
+            if (hue == bestHue) {
+                float s = hsv[1];
+                float v = hsv[2];
+                int bucket = (int) (s * 100) + (int) (v * 10000);
+                // Score by cumulative saturation * value.
+                float score = s * v;
+                Float oldTotal = rgbScores.get(bucket);
+                float newTotal = oldTotal == null ? score : oldTotal + score;
+                rgbScores.put(bucket, newTotal);
+                if (newTotal > highScore) {
+                    highScore = newTotal;
+                    // All the colors in the winning bucket are very similar. Last in wins.
+                    bestColor = rgb;
                 }
             }
         }